The present work was focused on the development and characterization of new hydrogel systems based on natural origin polymers, namely, alginate and carrageenan, into different formats and with adequate properties to sustain the viability of encapsulated cells, envisioning their application as cell delivery vehicles for tissue regeneration. Different formulations of alginate and carrageenan hydr...

Composite materials based on a titanium support and a thin, alginate hydrogel could be used in bone tissue engineering as a scaffold material that provides biologically active molecules. The main objective of this contribution is to characterize the activation and the functionalization of titanium surfaces by the covalent immobilization of anchoring layers of self-assembled bisphosphonate nerid...

Soft tissue reconstruction using tissue-engineered constructs requires the development of materials that are biocompatible and support cell adhesion and growth. The objective of this study was to evaluate the use of macroporous hydrogel fragments that were formed using either unmodified alginate or alginate covalently linked with the fibronectin cell adhesion peptide RGD (alginate-RGD). These m...

We report the spatiotemporal control of a 3D coculture by combining photocurable and chemically degradable hydrogels for coculture of embryonic stem (ES) cells with HepG2 cells. ES cells were encapsulated in micropatterned photocurable poly(ethylene glycol) (PEG) hydrogels. The cell-laden PEG hydrogels were then encapsulated in calcium-alginate (Ca-Alg) hydrogel containing HepG2 cells. The ES c...

Cell-laden hydrogel fibers are widely used as the fundamental building blocks to fabricate more complex functional three-dimensional (3D) structures that could mimic biological tissues. The control on the diameter of the hydrogel fibers is important so as to precisely construct structures in the above 3D bio-fabrication. In this paper, a pneumatic-actuated micro-extrusion system is developed to...

Four hydrophilic polymers in the form of beads - chitosan, alginate, alginate/polyvinyl alcohol (PVA), and chitosan-coated alginate - were used as supports for lipase immobilisation. Hydrogel beads were characterised by bead-size-distribution estimation, surface morphology studies, and polymer interactions assessment. Matrix performances - loading efficiency, immobilisation yield, enzyme activi...

Calcium alginate (CaALG) hydrogel beads and two sets of composite beads, formed from a combination calcium alginate/propylene glycol alginate/human serum albumin (CaALG/PGA/HSA) with the quaternary ammonium salt, (3-(trimethoxysilyl)propyl)-octadecyldimethylammonium chloride (QA), (CaALG/QA), were prepared. Bovine (BSA) was condensed glutaraldehyde (GLA) to form BSA/GLA hydrogel. The correspond...

Cell transplantation is a promising therapy for a myriad of debilitating diseases; however, current delivery protocols using direct injection result in poor cell viability. We demonstrate that during the actual cell injection process, mechanical membrane disruption results in significant acute loss of viability at clinically relevant injection rates. As a strategy to protect cells from these da...

In vitro ovarian follicle cultures may provide fertility-preserving options to women facing premature infertility due to cancer therapies. An encapsulated three-dimensional (3-D) culture system utilizing biomaterials to maintain cell-cell communication and support follicle development to produce a mature oocyte has been developed for the mouse. We tested whether this encapsulated 3-D system wou...

ABTRACT: We developed and experimentally verified an analytical model to describe diffusion of oligonucleotides from stable hydrogel beads. The synthesized alginate beads are Fe-cross-linked as well as polyelectrolyte-doped for uniformity and stability at physiological pH. Data on diffusion of oligonucleotides from inside the beads provide physical insights into the volume nature of the immobil...